C语言库atexit()函数

#include <stdio.h>
#include <stdlib.h>

void functionA () {
   printf("This is functionA/n");
}

int main () {

   /* register the termination function */
   atexit(functionA );

   printf("Starting  main program.../n");
   printf("Exiting main program.../n");

   return(0);
}